Using a recent cvs automake, I tried "make TAGS" in a separate object
directory, but the etags command got config.in without a $(srcdir)
path. Perhaps the @CONFIG@ in tags.am should be in the list that gets
uniquified and checked for needing $(srcdir). The same might apply to
$(LISP) there too, but I haven't tried that.
Actually, etags by default doesn't match anything in a config.in
containing only #undefs, so this isn't important, it's just to get the
target to go through. Maybe tags on the generated config.h would be
more use. Or maybe not.
